Safety shields are employed widely in the health care industry to eliminate or reduce the risk of accidental needle sticks. Safety shields have taken many forms, including shields that telescope along the needle cannula from a proximal position to a distal position. The distal tip of the needle cannula is exposed for use when the shield is in the proximal position. However the pointed distal tip of the needle cannula is covered when the shield is in the distal position.
Some shields are large and telescope over a syringe, needle holder or other medical implement. Some such large shields also include coil springs to propel the shield distally. The spring typically is locked in a collapsed condition around proximal portions of the medical implement when the shield is retained in the proximal position. An actuator is triggered after use of the medical implement to release the spring and drive the shield distally into a shielding disposition around the needle cannula.
Other shields are much smaller and are configured to telescope only along the needle cannula. The shield in these prior art devices may be connected to the syringe or the needle hub by a tether or a linked array of hinged arms to limit the range of movement of the shield relative to the needle cannula. Thus, the shield can be moved distally into surrounding relationship with the tip of the needle cannula. However, the tether or hinged arms prevent the shield from sliding completely off the needle cannula. Some shield assemblies of this general type include a spring mechanism for assisting a portion of the distal movement of the shield along the needle cannula. A shielding assembly of this general type is shown in U.S. Pat. No. 5,348,544 which is assigned to the assignee of the subject invention. The shielding assembly shown in U.S. Pat. No. 5,348,544 requires the user to initiate shielding by exerting digital pressure on one of the hingedly connected arms. This initial digital pressure will be resisted by the spring. However, after a certain range of movement, the hingedly connected arms will be positioned such that the spring assists the distal movement of the shield. The needle shielding device shown in U.S. Pat. No. 5,348,544 is very effective.
Some medical procedures employ a wing set for collecting fluid from a patient or delivering fluid to a patient. A wing set typically includes a length of flexible plastic tubing. One end of the tubing communicates either with a supply of fluid that will be delivered intravenously to the patient or with a container that will receive blood or other fluids drawn from the patient. The wing set further includes a needle assembly. The needle assembly includes a needle hub that has opposite proximal and distal ends. The proximal end of the hub is securely mounted to the end of the flexible plastic tubing remote from the container. The needle cannula is mounted to and projects from the distal end of the needle hub. The needle assembly of the typical wing set also includes a shield that is telescoped over the needle hub and that can be moved from a proximal position where the needle cannula is exposed to a distal position where the needle cannula is shielded. The needle assembly further includes at least one wing that projects from the needle hub or from the shield. The wing facilitates digital manipulation of the needle assembly. The wing also can be used to tape the needle assembly to the skin of the patient. Many needle assemblies include a pair of flexible wings that can be folded into face-to-face relationship with one another to facilitate digital manipulation. However, the wings can be folded into a coplanar disposition for taping the needle assembly to the skin of the patient.